外啮合微小齿轮泵流场模拟分析与优化

Flow Field Simulation Analysis and Optimization of Miniature External Gear Pump

为了揭示微小齿轮泵的几何参数与其工作性能之间的关系,利用Fluent动网格技术,对汽车尾气处理装置中微小齿轮泵进行二维数值模拟分析,探究顶隙、齿轮齿数等几何参数对微小齿轮泵流量和精度的影响规律。结果表明,在其他条件相同时,随着顶隙增大,平均流量逐渐变小,流量脉动率逐渐增大,顶隙由0.02 mm变化为0.3 mm时,平均流量减小约33%,流量脉动率增大约18%,精度降低;随着齿轮齿数增大,流量和流量脉动率均减小,齿轮齿数由14增大到28时,平均流量减小约54%,流量脉动率减小约95%,精度逐渐提高,齿轮齿数对流量脉动率的影响幅度明显高于对流量的影响效果。

In order to reveal the relation between geometrical parameter of miniature external gear pump and working performance,moving grid technology of the CFD software Fluent is presented to stimulate the internal fluid field of two-dimensional gear pump which is used for vehicle tail gas purifier. Then we explore the influence of different top clearances and gear teeth numbers on flow rate and precision of gear pump. The results show that when other conditions are the same,with the increase of top gap,the average flow rate decreases gradually while the flow pulse rate increases gradually. When the top clearance increases from 0.02 to 0.3 mm,the average flow decreases by about 33%,and the flow pulsation rate decreases by about 18% and the accuracy gradually increases. With the increase of gear teeth,both the average flow and flow pulsation rate decrease. When the number of gear teeth increases from 14 to 28,the average flow decreases by about 54%,and the flow pulsation rate decreases by about 95% and the accuracy gradually increases. The impact of number of gear teeth on flow pulsation rate is significantly higher than that on flow.